This invention relates to a chair having a tilt mechanism that allows the chair seat and back rest to tilt for the comfort of the user. More particularly, this invention relates to a chair having a tilt mechanism that allows the chair seat and back rest to tilt forwardly and rearwardly for the comfort of the user wherein the chair can be releasably locked in an upright, neutral position.
Many chairs, particularly office chairs, have weight activated backward tilt. By this it is meant that a user's weight exerts a force on the chair seat that is transferred through mechanical links to the chair back is able to tilt the back portion of the chair to a reclining position. When the user shifts his/her weight back to an upright posture, or when the user departs, the chair returns to is neutral position on its own. This phenomenon is often described as being “passive,” as opposed to a chair in which a user operates a lever to tilt the chair. When the user shifts his/her weight forward, a spring returns the back portion of the chair to its upright position. Some office chairs are arranged so that the seat portion also moves in response to tilting of the back portion. Sometimes the seat portion is fixed to the back portion so that they pivot about the same angle. In other chairs, commonly known in the industry as “synchro-tilt” chairs, the seat portion is arranged to be lowered or raised at a different rate than the rate of decline of the back portion, resulting in different angular movements of the back portion and the seat portion.
While many users prefer passive tilt capability in an office chair, some users prefer that the chair remain in its upright neutral position at all times. Still other users prefer to have an office chair with passive tilt capability for most tasks, but prefer to be able to lock the chair in its upright, neutral position for certain tasks or at certain times.
It is thus one object of the invention to provide a chair for use in an office or like environment and having a passive weight activated synchro-tilt mechanism, the chair comprising a tilt lock assembly by which the user can lock the chair in an upright, neutral position to prevent such forward and rearward tilting, at such times and under such circumstances as the user desires.